The main source of information for the appellate judges is the briefs filed by the parties. These briefs must follow the strict format set out in the Rules of Appellate Procedure (available online.)
In most appeals, only three briefs are filed–Brief of Appellant, Brief of Respondent, and Reply Brief. If there is a cross-appeal, the cross-appellant may file a fourth brief, Reply on Cross-Appeal. In some cases, an organization or advocacy group might be interested in how the appellate court decides the case and may ask for permission to file a friend of the court, or amicus curiae, brief.
The Brief of Appellant and the Brief of Respondent must explain the facts of the case, including a citation to show the judges where in the appellate record each fact can be found. The briefs must also explain the applicable legal principles and show why those principles indicate that the party should win the appeal.